Immigration and emigration significantly contribute to evolution by altering allele frequencies within populations. When individuals migrate into a population (immigration), they can introduce new genetic material, changing the genetic makeup and potentially increasing genetic diversity. Conversely, when individuals leave a population (emigration), they can remove certain alleles from that population. These changes in allele frequencies can affect the population's overall evolution, impacting traits such as adaptability, survival, and reproductive success.
This dynamic process helps drive natural selection, as populations that are more genetically diverse may be better equipped to cope with changing environments, diseases, and other selective pressures. Consequently, the interplay of immigration and emigration is crucial for understanding evolutionary processes, especially in relation to the genetic health and sustainability of populations over time.